Syringe shield



April 24, 1928.

w. E. STEWART SYRINGE SHIELD Fired June 22. 1926 INVENTOR Fatentecl Apr.24, 1928.

UNITED STATES PATENT OFFICE;

WILLIA EVERE'I'TE STEWART, F nnsnvInL 'r nn ss S I NOBTO EISEiE acoMrANY; OF NASHVILLE, TENNESSEE, .A CORPORATION OF DELAWARE.

SYR-INGE SHIELD.

Application filed June 22,

needle may be placed in it prior to insertion of the syringe, so thatthe shield with the needle, and the syringe, may be separatelysterilized, and the syringe thereafter inserted in theshield andoperatively connected with the needle; to provide a shield which protects the syringe tip or part which enters the needle base and preventsbreakage of the tip, this beingespecially important inthe case of aglass syringe; to apply the reactive force occasioned by pressure on thesyringe plung er, through the shield to the needle base,

which insures retention of the needle upon the syringe tip, preventsdisplacement of the needle from the tip by hydraulic pressure, andespecially in the case 01 a glass syringe tube, avoids application ofstrain to the bead at the: upper end of the tube; to provide a shield offlexible or adjustable construction sothat it is readilyand practicallyautomatically adaptable to syringes of varying diameters, and to"provide a simple, secure and easily operated locking device for clampingthe needle base in the shield and securing the shield to the syringe.

'The' characteristics and advantages of the invention are furthersuflicientl'y explained in connection with the following" detaildescription of the accompanying drawing. which shows a representativeembodiment of the invention. Aft-er considering this example, skilledpersons will understand that many variations maybe made, and Icontemplate the'einple'yment of any structures that are pr oper lywithinthe scope of the appended claims.

Fig; 1 is a perspeotiveview of a shield embodying the" invention in oneform, properly applied and secured to'a glass syringe and a needle ofthe 'Luer type, as representative of knownor standardsyringes andneedles with which theshieljd is designedto co-operate.

1926. Serial No. 117393.

Fig, 2 shows the shield,s'yringe and needle separated. I

Fig. 3 is a longitudinal section ofthe lower part of the shield appliedand secured to the syringe and needle.

Fig. 4 is a perspective view of a known type of glass'syringe andneedle, the syringe being provided with the usual finger grip,foruse'without ashielcl.

. While, as indicated above, the present shield is adapted or adaptablefor use with various types of syringes and needles including metal orother syringes, and needles of other than the Luer type, thecharacteristics and advantages of the invention will be understood byexplanation of its co-operation with a glass barrel syringe of knowntype and with Luer needles adapted for such glass syringes. Theinvention structure is therefore shown in the drawings as especial- 1yadapted to and used in connectionwitha syringe and needle of the statedtypes.-

This. glass syringe consists of a tube or barrel 1 having an integraltip 2 tapered and ground to have a tight friction fit witlr in thetapered socket 3 of the base 4 of a hypodermic needle 5, which, in thisinstance,

ton 6 slidesin the tube and the tube and piston are ground to provide atight and practically leak-proof'fit. At the upper: end of the piston isa flattened" thun'ib knob 7. These glass tubes 1 usually have at theupper end a reenforcing bead 8, and" in customary practice a finger grip10 having projecting finger pieces 11 is slipped over .the: tube andrests against the under face of the bead,'so that when the fingers ot'the operator are placed beneath the finger pieces ll, and the thumb isapplied to knob 7 to force thepiston into the tube, the pressurereaction is taken; by the linger grip and applied to the bead '8; Sincethetube 1 is usually of thin section, this pressure is apt. toica'usebreak age. The needlebase also, while it is applied to the't'ip 2 with atight friction fit, isnot positively secured, and" hydraulic pressureiiiTo avoid these difficulties or disadvantages of the ordinary glass typesyringe, and also to realize the objects or advantages above andhereafter pointed out in connection with syringes and needles of theseand other types, .1 provide the shield structure generallydesignated asS, the drawing showing a single representative embodiment which ispreferred in many cases, but which may evidently be varied as to detailsof structure or arrangement within the principles of the invention andwithin the limits defined by the claims appended.

This shield comprises a tubular body 20 at theupper end of which a"inger grip 21. is secured. The lower part of the tube is renderedadjustable or flexible by severing it alongv one, or preferably two,opposite longitudinal lines, as at Fig. 1, producin; the arate movableor adjustable lower portions 23 of generally semi-cylindrical contour.izrbore the longitudinal slots or divisions the tube is preferably cutaway or apertured at one or preferably two opposite sides, as shown,this tube formation producing long, narrow part-cylindrical members 24;cormecting the upper tubular portion 20 and the lower adjustable members23. The relatively narrow connecting members 24 are flexible orresilient and therefore support the lower gripping members forsubstantial movability toward and from each other. The lower grippingmembers 23 terminate in nose or chuck portions 26 of reduced diameter,and the inner face of each of the chuck members is grooved, as at 27, toreceive the upper flange or bead 28 of a Luer or othertype of needlebase 4. Any suitable clamping or locking device may be provided,represented in this embodiment by a ring 30 placed about the tube andprevented from down vard displacement by a pin 31 inserted in one of theclamping members 23. This pin also cooperates with a bayonet slot 32 inthe ring, as explained hereafter.

The inner diameter of the upper portion of the tube 20 is dimensioned totit syringe tubes within a desired range of sizes and it-will be evidentfrom the following operative description, that the external diameter ofthe syringe used with any particular :ihield may vary withinconsiderable limits.

The base of a Luer or other type of needle may be inserted between thechuck jaws 26 while they are separated (with the locking ring 30 in anupward position. as

in Fig. 2) and temporarily held in the shield by the natural resilientpressure of the connecting strips or by moving the ring 30 downwardtoward the pin 31. The shield with the needle may then be sterilized anda separately sterilized syringe may be inserted through the upper'end ofthe shield until. the tip 2 enters the needle socket 3 and is firmlysecured by a twisting movement, and if necessary the lower flange 44) ofthe needle base may be grasped and turned to insure tight connectionwith the tip. position by moving the locking ring down until pin 31enters the axial portion of the bayonet slot and then turning the ringto cause the pin to enter the diagonal or circumferential part of theslot to move the ring to final locking position, whereupon the innerfaces of the clamping members 2 grip the lower portion of the syringetube and the chuck members 26 grip the needle base. The looking orgripping action of the member- 23 and 26 in co-operation with the ringmay be insured by so shaping the exterior faces of the members 23 thatthey flare slightly downwardly, this flare or taper being in most casestoo slight foraccurate representation in the drawing.

If it is not desired to apply the needle to the shield before thesyringe is inserted, the syringe may first be inserted in the shieldwhile the gripping members 33 are laterally retracted; the needle isthen applied and secured to the tip 2, and the ring 30 is moved tolocking position whereupon the chuck members firmly engage the needlebase, as previously described.

ll hen the finger grip 21 is grasped by the fingers and the thumb isapplied to knob 7 to make an injection, the reactive force is appliedthrough the shield to the needle base I and through it to tip 2 and thelower portion of the syringe tube. In this way the needle is firmly heldupon the tip without possibility of displacement by hydraulic pressure,and any strainupon the upper portion of the tube or head 8 is avoided,and therefore there is no possibility of tube breakage caused byinjection pressure. The side apertures in the shield permit readyinspection of the syringe and its contents. The shield covers the majorportion of the tube and sufficiently prevents it from any reasonablepossibility of breakage by contact with hard objects. Especially, thelower part of the shield or the chuck jaws 26 in co-operation with theneedle base enclose the glass tip 2 and prevent breakage thereof. Therange of movement or adjustability of the lower or clamping members 23with-the chuck members 26 is such that the shield may be secured toglass or other syringe tubes of dillerent diameters within a substantialrange. The locking device is easily manipulated even when the operatoris using rubber gloves and the gloves are wet. Other features ofstructural and operative advan tage will be sufficiently understood fromthe previous explanations.

I claim I I I 1. A syringe shield comprising a tubular body having abifurcated lower portion, the

The shield is then lirmly locked in furcations normally resiliently heldin spaced relation, and meansco-operating with the furcations forpressing them together to removably clamp a needlebase and the lowerportion of a syringe barrel or tube.

2. A syringe shield comprising a tubular body having a bifurcatedlowerportion, the furcations normally resiliently held in spaced relation,means co-operating with the furcations to press them together toremovably clamp a needle base and the lower por tion of a syringe barrelor tube, and a finger grip at the upper end of the. tubular body.

3. A syringe shield comprising a tubular body having a bifurcated lowerportion, the furcations normally resiliently held in spaced relation,and means co-operating with the fur-cations for pressingthem together toremovably clamp a needle base and the lower portion of a syringe barrelor tube, the body having in at least one side a sight opening ofsubstantial length and width.

at. A syringe shield comprising a tubular metal body including oppositenarrow portions terminating in part-cylindrical gripping members, saidmembers being adapted to grip the lower portion of a syringe tube andbeing provided with chuck members conformed to receive and grip a needlebase.

5. A syringe shield comprising a tubular metal body including oppositenarrow portions terminating in part-cylindrical gripping members, saidmembers being adapted to grip the lower portion of a syringe tube andbeing provided with chuck members conformed to receive and grip a needlebase, and locking means for releasably clamping said gripping and chuckmembersupon a syringetube and needle base;

6. A syringe shield-comprising a tubular metal body including oppositenarrow. portions terminating in part-cylindrical grip-- ping members,said members being adapted to grip the lower portion of a syringe tubebody provided with resiliently retractable gripplng members, and lockingmeans, said gripping members including chuck formations designed to gripand secure a needle base either before or after insertion of a syringewithin the body, said members also adapted to retractably grip the lowerportion of the syringe, and a finger grip at the upper end of thetubular body, the parts being constructed and arranged to apply thereaction of injection pressure through the shield to the lower portionof the syringe.

9. A syringe shield comprising a metal tube having opposite sideportions cut away for a substantial distance producing sight openingsand also providing opposite narrow resilient strips connecting upper andlower portions of the body, the lower end of the tube beinglongitudinally slotted producing convergently movable semi-cylindri calclamping members terminating in chuckjaws conformed to receive and gripa needle base, and clamping means co-operating with said clampingmembers to secure them in contact with the needle base and the lowerportion of a syringe inserted in the shield.

Signed at Nashville in the county of Davidson and State of Tennesseethis 19 day of June, A. D. 1926.

WILLIAM EVERETTE STEWART.

